The present invention relates to aryl substituted alkylsilanes and a preparation method thereof. More particularly, the present invention relates to aryl substituted alkylsilanes and a preparation method thereof by reacting substituted benzenes with aryl substituted alkylsilanes in the presence of Lewis acid catalysts.
Since Friedel and Crafts first reported the alkylation reaction of benzene with alkyl halide in the presence of aluminum chloride catalyst in 1877, the Friedel-Crafts type alkylation reaction has been widely used as a synthetic procedure in organic synthesis(R. M. Roberts and A. A. Khalaf, Friedel-Crafts Alkylation Chemistry, Marcel Dekker, Inc., NY, 1984).
Chernyshev and Dolgaya reported the Friedel-Crafts type alkylation of (chloroalkyl)trichlorosilanes to substituted benzenes to produce (trichlorosilyl)-alkylbenzenes [E. A. Chernyshev and M. E. Dolgaya, Zhur. Obschchei Khim, 25, 2469(1955)]. ##STR2##
They reacted (dichloromethyl)silane or (dichloroethyl) silane with benzene, chlorobenzene, or toluene to produce two phenyl groups substituted alkylchlorosilanes [E. A. Chernyshev, M. E. Dolgaya, and A. D. Petrov, Zhur. Obschchei Khim, 28, 613 (1958)]. They also reacted (chloropropyl)silane with benzene, chlorobenzene, toluene, biphenyl, or biphenyl ether to produce phenyl groups substituted propylchlorosilanes [E. A. Chernyshev, M. E. Dolgaya, and Yu. P. Egorov, Zhur. Obschchei Khim, 28, 2829(1958)]. ##STR3##
Recently, we reported the Friedel-Crafts type alkylation of substituted benzenes with allyldichlorosilanes (Jung, I. N.; Yoo, B. R.; Lee, B. W.; Yeon, S. H., U.S. Pat. No. 5,527,938) and vinylchlorosilanes (Korea Patent Application No. 95-48114). ##STR4##
(Chloroalkyl)silanes can be easily prepared by the photochlorination of alkylsilanes on a large scale. In this process, polychlorinated alkylsilanes are inevitably produced as byproducts, because the chlorinated organic moieties are more susceptible toward the chlorination [R. H. Krieble and J. R. Elliott, J. Am. Chem. Soc., 67, 1810 (1945)]. However, polychlorinated alkylsilanes do not find any applications in industry and are disposed. Thus, it is very important to develop a method to convert the polychlorinated byproducts from chlorination reactions of alkylchlrosilanes to useful organosilane compounds. We found that the chloro groups of polychlorinated alkylsilanes can be converted to the corresponding polyaryl substituted alkylsilanes by the Friedel-Crafts type alkylation with particularly more than two halogen atoms substituted benzenes in the presence of Lewis acid catalysts. This method can be applied to the alkylsilane compounds having not only one or two chlorine atoms but also three chlorines.